A nonuniform density of subthreshold, rapidly inactivating potassium channels regulates signal propagation in the dendrites of CA1 pyramidal neurons of the hippocampus. This nonuniform distribution (with higher expression in the dendrites than in the soma) means that the electrical properties of the dendrites are markedly different from those of the soma. Incoming synaptic signals are shaped by the activity of these channels, and action potentials, once initiated in the axon, progressively decrease in amplitude as they propagate back into the dendrites. By combining patch clamp recording in brain slices of the hippocampus with molecular biology techniques, the Molecular Neurophysiology and Biophysics Unit investigates the electrophysiological properties and molecular nature of the voltage-gated channels expressed in CA1 dendrites, how their expression is regulated, and their role in synaptic integration and plasticity.